Biologists separate life into three phases: development, aging and late life. But a growing body of research now suggests that there is a fourth phase immediately preceding death that scientists have dubbed the “death spiral.”
Although most of the “death spiral” research has focused on fruit flies, scientists think these studies can offer valuable insight into the last stage of human life as well.
“We believe this is part of the process of, basically, genetically programmed death,” Laurence Mueller, chair of the Department of Ecology and Evolutionary Biology at the University of California, Irvine, said in an interview with Live Science. [What Are Your Odds of Dying From …]
Expiring fruit flies
Over the past decade, several studies of fruit flies have suggested this spiral toward death can be seen in the drop in reproductive rate (fecundity), according to a review of this research by Mueller and his colleagues, published earlier this year in the journal Biogerontology. For instance, researchers reporting in 2015 in The Journals of Gerontology found that the first day a female fly laid zero eggs was a significant predictor of death: Indicators of fecundity started to decline about 10 days before young female fruit flies laid zero eggs. The researchers think that whatever leads to the flies’ deaths also affects their ability to reproduce in their final days.